Googler | 9398cc3 | 2022-12-02 17:21:52 +0800 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
Googler | af606d2 | 2022-10-26 21:40:12 -0700 | [diff] [blame] | 2 | /* |
| 3 | * MPLS GSO Support |
| 4 | * |
| 5 | * Authors: Simon Horman (horms@verge.net.au) |
| 6 | * |
Googler | af606d2 | 2022-10-26 21:40:12 -0700 | [diff] [blame] | 7 | * Based on: GSO portions of net/ipv4/gre.c |
| 8 | */ |
| 9 | |
| 10 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| 11 | |
| 12 | #include <linux/err.h> |
| 13 | #include <linux/module.h> |
| 14 | #include <linux/netdev_features.h> |
| 15 | #include <linux/netdevice.h> |
| 16 | #include <linux/skbuff.h> |
Googler | af606d2 | 2022-10-26 21:40:12 -0700 | [diff] [blame] | 17 | |
| 18 | static struct sk_buff *mpls_gso_segment(struct sk_buff *skb, |
| 19 | netdev_features_t features) |
| 20 | { |
| 21 | struct sk_buff *segs = ERR_PTR(-EINVAL); |
| 22 | u16 mac_offset = skb->mac_header; |
| 23 | netdev_features_t mpls_features; |
| 24 | u16 mac_len = skb->mac_len; |
| 25 | __be16 mpls_protocol; |
| 26 | unsigned int mpls_hlen; |
| 27 | |
| 28 | skb_reset_network_header(skb); |
| 29 | mpls_hlen = skb_inner_network_header(skb) - skb_network_header(skb); |
Googler | af606d2 | 2022-10-26 21:40:12 -0700 | [diff] [blame] | 30 | if (unlikely(!pskb_may_pull(skb, mpls_hlen))) |
| 31 | goto out; |
| 32 | |
| 33 | /* Setup inner SKB. */ |
| 34 | mpls_protocol = skb->protocol; |
| 35 | skb->protocol = skb->inner_protocol; |
| 36 | |
| 37 | __skb_pull(skb, mpls_hlen); |
| 38 | |
| 39 | skb->mac_len = 0; |
| 40 | skb_reset_mac_header(skb); |
| 41 | |
| 42 | /* Segment inner packet. */ |
| 43 | mpls_features = skb->dev->mpls_features & features; |
| 44 | segs = skb_mac_gso_segment(skb, mpls_features); |
| 45 | if (IS_ERR_OR_NULL(segs)) { |
| 46 | skb_gso_error_unwind(skb, mpls_protocol, mpls_hlen, mac_offset, |
| 47 | mac_len); |
| 48 | goto out; |
| 49 | } |
| 50 | skb = segs; |
| 51 | |
| 52 | mpls_hlen += mac_len; |
| 53 | do { |
| 54 | skb->mac_len = mac_len; |
| 55 | skb->protocol = mpls_protocol; |
| 56 | |
| 57 | skb_reset_inner_network_header(skb); |
| 58 | |
| 59 | __skb_push(skb, mpls_hlen); |
| 60 | |
| 61 | skb_reset_mac_header(skb); |
| 62 | skb_set_network_header(skb, mac_len); |
| 63 | } while ((skb = skb->next)); |
| 64 | |
| 65 | out: |
| 66 | return segs; |
| 67 | } |
| 68 | |
| 69 | static struct packet_offload mpls_mc_offload __read_mostly = { |
| 70 | .type = cpu_to_be16(ETH_P_MPLS_MC), |
| 71 | .priority = 15, |
| 72 | .callbacks = { |
| 73 | .gso_segment = mpls_gso_segment, |
| 74 | }, |
| 75 | }; |
| 76 | |
| 77 | static struct packet_offload mpls_uc_offload __read_mostly = { |
| 78 | .type = cpu_to_be16(ETH_P_MPLS_UC), |
| 79 | .priority = 15, |
| 80 | .callbacks = { |
| 81 | .gso_segment = mpls_gso_segment, |
| 82 | }, |
| 83 | }; |
| 84 | |
| 85 | static int __init mpls_gso_init(void) |
| 86 | { |
| 87 | pr_info("MPLS GSO support\n"); |
| 88 | |
| 89 | dev_add_offload(&mpls_uc_offload); |
| 90 | dev_add_offload(&mpls_mc_offload); |
| 91 | |
| 92 | return 0; |
| 93 | } |
| 94 | |
| 95 | static void __exit mpls_gso_exit(void) |
| 96 | { |
| 97 | dev_remove_offload(&mpls_uc_offload); |
| 98 | dev_remove_offload(&mpls_mc_offload); |
| 99 | } |
| 100 | |
| 101 | module_init(mpls_gso_init); |
| 102 | module_exit(mpls_gso_exit); |
| 103 | |
| 104 | MODULE_DESCRIPTION("MPLS GSO support"); |
| 105 | MODULE_AUTHOR("Simon Horman (horms@verge.net.au)"); |
| 106 | MODULE_LICENSE("GPL"); |